My 2011 JGC did the same thing. It had to do with something in the lower lumbar support mechanism. Since that part moved in my seat, it developed a popping sound when accelerating or decelerating. I thought the seat mount was a problem but it was the lower inside of the seat related to the lumbar mechanism.

Anyway, the dealer totally messed my seat up with the repair. They broke all the hangers and plastic parts that snap on. They wanted me to accept it that way. After multiple tries and trips to that dealer (Tr-County - Heath, Ohio) I went to another dealer. I would never recommend TRI-County Jeep to anyone!!!!!!!!!!!!!! I went to Liberty Jeep, New Albany, Ohio and they were able to eventually kind of fix it. I had the Jeep Customer Care involved and they were useless! The seat popping is fixed and they replaced the hangers in the seat back and the side plastic seat bottom, but there is still one plastic part that keeps popping out and won't stay in. This is because the metal base at the seat bottom is bent and doesn't align properly. Jeep should have replaced the entire seat but wouldn't because it went out of warrant near the beginning of the process. I ended up making 18 trips to the dealer to try and fix this problem, so good luck getting yours fixed!

I purchased a 2014 Limited about 5 days ago and noticed the cracking from the lumbar area on the second day of ownership.

I tallied a list of issues for my salesman and dropped it off to him on Saturday.
The lumbar creaking issue was on the list...along with the passenger door sounding like a tin-can (hollow) when you knock on it or close it too hard, but that's a separate issue entirely.

I'm hoping the service department at this dealership knows how to deal with the issue- if not I'm going to gather as much information as possible about the problem and drop it off to them to figure out. I might actually just preemptively get some printouts at work and just leave them in the car for when I drop it off...

I already did the uConnect update myself following some instruction on this forum and it was extremely simple. It seems like another forum member actually fixed the problem with the creaking seat by removing the seatback and unhooking something...I might at least take a look at that before I bring it in- it might be a while before I can get an appointment with service I guess because of the recalled shifters (which I also need).

How do you remove the driver's side seat back on a 2015 Overland? I've got the annoying pop sound going over bumpy roads or accelerating or shifting weight. I'm pretty sure it's the drivers seat but hard to tell if coming from bottom of seat or lumbar area.

I didn't do it myself and you may need special tools. It has special hangers that it connects too and the deal broke mine and it all had to be replaced. Goggle it or look at youtube to see if anyone has posted a How To. Sorry I can't provide any additional guidance.